The whole Vader/Luke duel in The Empire Strikes Back is fantastic, if you ask me. It’s got the best fight choreography and stunt work of any fight in the original trilogy, not to mention the beautiful cinematography and perfect pacing. Of course, the duel starts in the carbon freezing chamber and ends on the reactor shaft gantry where Vader reveals the horrible truth of Luke’s parentage. But right in the middle lies another Cloud City location, one of my favorites: the reactor control room.
Built around this time 40 years ago in Stage 1 at Elstree Studios, this set comprised the underbelly of the carbon freezing chamber, the hallway where Luke flies out the big circular window, and a metallic tunnel that connects those two areas. I love how quietly eerie these areas are as Luke creeps through, searching for Vader. And thank the maker – Star Wars: The Blueprints documents this set pretty thoroughly with plans, elevations, and details.
The first step in recreating this set was to bring all those technical drawings into 3D space together with the correct scale and orientation and location. Unfortunately, I don’t know exactly where this set was situated inside Stage 1, or at what angle. I took a best guess, taking comfort in the fact that the drawings would at least all be the right sizes and they’d be positioned correctly relative to each other. In Blender’s viewport, that looked something like this:

Kind of a mess, but it’s just the kind of mess I needed to bring this thing to life. From there, I was able to begin building the rostrums (platforms) upon which the set…sat.

The L-shaped rostrum on the left was 16 feet above the studio floor and it supported the area beneath the carbon freezing chamber that Luke drops into after Vader falls. The larger 10-foot-high rostrum below was for the area with the big circular window and the hallways. (They had to build the set elevated above the floor to accommodate the grates that slide shut after Luke passes through the tunnel; these were a practical effect, so the bottom grate had to fit below the set.)
You can also see that I’d already started working on the walls of the set by this point, and the progress continued pretty quickly:
You can see the aluminum tunnel or tube that connects the two main areas of the set. I never realized from watching the film that it was angled downward! (Fun fact: it’s a 13-degree angle, which comes out to 77 degrees from vertical…now, where have I heard the number 77 in Star Wars history before?)

I like that render. I was trying to roughly match the angle from which we see Luke enter the tube. (The lighting is too bright; it’s since been dialed down to match the film.)
Below, you can see more progress on various areas of the set, including a large, grayish-blue backdrop that in real life was painted to look like the immense reactor shaft outside the window:
All the work here was on the lower area of the set where most of this scene takes place. But then I hopped up to the other rostrum to work on the area beneath the carbon freezing chamber, and I got a surprise: there was more to that area than you can see in the film. This is all we’re ever given in the final cut:

Just a little bit of dark, greebly wall outside the mouth of the tube. But the technical drawings depict this area as a (section of a) circular passageway with a camera rostrum at one end and walls that increase in height as they get further away from the camera. This indicates that the filmmakers intended to get footage of Luke from that camera rostrum. It would have been an angle perpendicular to this one, looking down the passageway toward the left side of this shot. Sadly, I can’t find any behind-the-scenes shots of this area or anything, so all I have to go off of is the above shot and the technical drawings.
Gives some sense of what the area would have looked like, I think. But I’ll do you one better – here’s a shot approximating the unused angle I described above!

That’s the (incomplete) mouth of the aluminum tube near the center. I angled the camera so you can see the tops of the set walls. Notice how they increase in height, like I described.
The most recent step was to start the last major area of the set: the curved hallway seen behind Luke as we watch Vader approach him from over the Sith Lord’s shoulder. Unlike the rest of this set, this hallway was built with forced perspective – rather than following an actual circular path like it appears to, it’s scrunched up toward the back to look longer than it actually is. Here’s a view from within the set showing the illusion, followed by a view from above that gives a bit of a sense of how the passage shrinks away toward the back:
Lots of details are still missing, but all the major pieces are in place now, save for one: the big circular window that Luke gets sucked out of. The drawings just show a simpler rectangular window in that wall, so it’s going to take a little more work to replicate the final design seen in the film. More on that soon, I hope!